Help with Kouki Trueno bumper cover install!!!

[thillUSA]

I am in need of some help with the installation of a kouki trueno bumper cover on my 1985 sr5 corolla usdm. I have the brackets on order to install. I know I need them, but I can't seem to place how to mount the bumper correctly. Do I need to remove the factory steel bumper? If you could point me in the right direction I would be very grateful. I also tried to fit the bumper and and it would not fit around the factory sr5 bumper because the actual bumper is too thick in reference to the area to bolt up the trueno bumper cover. Any help would be much appreciated. Maybe a write up or link!?

I can add photos if someone is better visually looking at the problem.